Horses, Mongolian Steppe

An ocean of green, Mongolia is the most sparsely populated country in the world, with just under three million people in a landmass larger than Alaska. Mongolian culture—physical, mobile, self-reliant, and free—developed out here on the steppe. "When people move to Ulaanbaatar, they bring that mentality with them," says Baabar, a well-known publisher and historian.

See more pictures from the October 2011 feature story "The Urban Clan of Genghis Khan."

Coral Reef, Red Sea

Photograph by Thomas P. Peschak, National Geographic

Rarely visited, the reefs off Saudi Arabia in the northern Red Sea are some of the most undisturbed in the region. Sunlight penetrates deep into the clear waters, enabling lush gardens of corals to flourish along these wave–washed coasts.

See more pictures from the March 2012 feature story "The Seas of Arabia."

Oil Tanker, Persian Gulf

Photograph by Thomas P. Peschak, National Geographic

A relic of the Iran-Iraq war, this oil tanker was scuttled near the Kuwait-Iraq border on Saddam Hussein’s orders, to block access by sea to southern Iraq. Kuwaiti authorities are reluctant to remove the vessel for fear of damaging the wetlands of nearby Bubiyan Island, an important fish nursery and seabird breeding ground.

See more pictures from the March 2012 feature story "The Seas of Arabia."

High Tide, Indonesia

As night falls and the tide rises on the Indonesian island of Pulau Balai, off the west coast of Sumatra, more than an inch of water washes into the home of 20-year-old Busrani. In March 2005 a seafloor earthquake lowered the island by three feet. Busrani can't afford to raise his floor, which floods at every high tide.

See more pictures from the February 2012 feature story "The Calm Before the Wave."

White Pocket, Arizona

Miniature lakes reflect the sky in White Pocket, one of the geological spectacles on the Paria Plateau. Over the eons, groundwater has leached the color out of the Navajo sandstone here, and the weather has broken its surface into irregular polygons.

See more pictures from the February 2012 feature story "Rock of Ages."